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39 pages, 1990 KiB  
Review
Enhancing Biodiesel Production: A Review of Microchannel Reactor Technologies
by Koguleshun Subramaniam, Kang Yao Wong, Kok Hoe Wong, Cheng Tung Chong and Jo-Han Ng
Energies 2024, 17(7), 1652; https://doi.org/10.3390/en17071652 (registering DOI) - 29 Mar 2024
Abstract
The depletion of fossil fuels, along with the environmental damages brought by their usage, calls for the development of a clean, sustainable and renewable source of energy. Biofuel, predominantly liquid biofuel such as biodiesel, is a promising alternative to fossil fuels, due to [...] Read more.
The depletion of fossil fuels, along with the environmental damages brought by their usage, calls for the development of a clean, sustainable and renewable source of energy. Biofuel, predominantly liquid biofuel such as biodiesel, is a promising alternative to fossil fuels, due to its compatible direct usage within the context of compression ignition engines. However, the industrial production of biodiesel is far from being energy and time efficient, which contributes to its high production cost. These inefficiencies are attributed to poor heat and mass transfer of the transesterification reaction. The utilisation of microchannel reactors is found to be excellent in escalating heat and mass transfer of the reactants, benefitting from their high surface area-to-volume ratio. The microchannel also intensifies the mixing of reactants via the reactor design, micromixers and the slug flow patterns within the reactor, thus enhancing the contact between reactants. Simulation studies have aided in the identification of mixing regimes within the microchannel reactors, induced by various reactor designs. In addition, microwave irradiation heating is found to enhance biodiesel production by localised superheating delivered directly to the reactants at a molecular level. This enables the reaction to begin much earlier, resulting in rapid biodiesel production. It is postulated that the synergy between microchannel reactors and microwave heating would catapult a pathway towards rapid and energy-efficient biodiesel production by enhancing heat and mass transfer between reactants. Full article
(This article belongs to the Special Issue Sustainable Biofuels for Carbon Neutrality)
24 pages, 4447 KiB  
Article
Advancing Food Preservation: Sustainable Green-AgNPs Bionanocomposites in Paper-Starch Flexible Packaging for Prolonged Shelf Life
by Federico Trotta, Sidonio Da Silva, Alessio Massironi, Seyedeh Fatemeh Mirpoor, Stella Lignou, Sameer Khalil Ghawi and Dimitris Charalampopoulos
Polymers 2024, 16(7), 941; https://doi.org/10.3390/polym16070941 (registering DOI) - 29 Mar 2024
Abstract
In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties [...] Read more.
In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability. Full article
(This article belongs to the Special Issue Natural-Based Biodegradable Polymeric Materials II)
18 pages, 1006 KiB  
Article
Photon Phase Delay Sensing with Sub-Attosecond Uncertainty
by Fabrizio Sgobba, Andrea Andrisani and Luigi Santamaria Amato
Sensors 2024, 24(7), 2202; https://doi.org/10.3390/s24072202 (registering DOI) - 29 Mar 2024
Abstract
The application of statistical estimation theory to Hong–Ou–Mandel interferometry led to enticing results in terms of the detection limit for photon reciprocal delay and polarisation measurement. In the following paper, a fully fibre-coupled setup operating in the telecom wavelength region proves to achieve, [...] Read more.
The application of statistical estimation theory to Hong–Ou–Mandel interferometry led to enticing results in terms of the detection limit for photon reciprocal delay and polarisation measurement. In the following paper, a fully fibre-coupled setup operating in the telecom wavelength region proves to achieve, for the first time, in common-path Hong–Ou–Mandel-based interferometry, a detection limit for photon phase delay at the zeptosecond scale. The experimental results are then framed in a theoretical model by calculating the Cramer–Rao bound (CRB) and, after comparison with the obtained experimental results, it is shown that our setup attains the optimal measurement, nearly saturating CRB. Full article
(This article belongs to the Section Optical Sensors)
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18 pages, 628 KiB  
Article
Lipase-Catalyzed Preparation and Optimization of Structured Phosphatidylcholine Containing Nervonic Acid
by Xun Ang, Hong Chen, Jiqian Xiang, Fang Wei and Siew Young Quek
Molecules 2024, 29(7), 1539; https://doi.org/10.3390/molecules29071539 (registering DOI) - 29 Mar 2024
Abstract
This study investigated the incorporation of nervonic acid into the chemical structure of phosphatidylcholine via a lipase-catalyzed acidolysis reaction to obtain a functional phospholipid. Lipase immobilization was conducted, and Amberlite XAD7-HP was selected as a carrier to immobilize phospholipase A1 (PLA1 [...] Read more.
This study investigated the incorporation of nervonic acid into the chemical structure of phosphatidylcholine via a lipase-catalyzed acidolysis reaction to obtain a functional phospholipid. Lipase immobilization was conducted, and Amberlite XAD7-HP was selected as a carrier to immobilize phospholipase A1 (PLA1) for subsequent experiments. The main acidolysis reaction parameters, including enzyme load, substrate ratio, temperature, and water content, were studied against the reaction time. The optimum reaction conditions obtained were enzyme load, 20%; reaction temperature, 55 °C; water content, 1%; and reaction time, 9 h. The maximum incorporation of nervonic acid into phosphatidylcholine was 48 mol%, with PC recovery at 61.6 mol%. The positional distribution of structured phosphatidylcholine shows that nervonic acid was found in the sn-1 position due to enzyme specificity and in the sn-2 position, possibly due to acyl migration. Full article
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22 pages, 2672 KiB  
Article
Enhancing Post-Harvest Resilience: Investigating the Synergistic Effects of Essential Oil Combinations on Biochemical Profiles in Botrytis cinerea-Infected Apples
by Sinem Karakus
Horticulturae 2024, 10(4), 341; https://doi.org/10.3390/horticulturae10040341 (registering DOI) - 29 Mar 2024
Abstract
This study explored the impact of essential oil combinations on Botrytis cinerea-infected apples, focusing on how these treatments affect the levels of amino acids, anthocyanins, organic acids, phenolic compounds, and hormones. We discovered significant differences in amino acid concentrations, particularly asparagine, serine, [...] Read more.
This study explored the impact of essential oil combinations on Botrytis cinerea-infected apples, focusing on how these treatments affect the levels of amino acids, anthocyanins, organic acids, phenolic compounds, and hormones. We discovered significant differences in amino acid concentrations, particularly asparagine, serine, histidine, glycine, and arginine, between control and fungus-treated apples. Preventive measures notably increased anthocyanins like delphinidin-3-glycoside and peonidin-3-glycoside, while combinations such as thymol + fungus balanced anthocyanin profiles effectively. Organic acid and phenolic compound analyses showed that curative strategies generally increased concentrations, with the thymol + cineole + fungus treatment being especially effective. Hormonal analysis highlighted the benefits of preventive measures in raising indole-3-acetic acid and gibberellic acid levels, whereas curative treatments increased abscisic acid and salicylic acid concentrations. The combination of cineole and thymol with fungicide emerged as a potent strategy for enhancing phenolic content. These findings underscore the potential of specific essential oil combinations in improving the biochemical composition of B. cinerea-infected apples, offering new avenues for enhancing fruit quality and sustainability in the agriculture sector. Full article
(This article belongs to the Special Issue Improvements in Apple: From Breeding to Cultivation and Postharvest)
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16 pages, 6044 KiB  
Article
HepG2BD: A Novel and Versatile Cell Line with Inducible HDV Replication and Constitutive HBV Expression
by Matthieu Blanchet, Léna Angelo, Yasmine Tétreault, Marwa Khabir, Camille Sureau, Andrew Vaillant and Patrick Labonté
Viruses 2024, 16(4), 532; https://doi.org/10.3390/v16040532 (registering DOI) - 29 Mar 2024
Abstract
Individuals chronically infected with hepatitis B virus (HBV) and hepatitis Delta virus (HDV) present an increased risk of developing cirrhosis and hepatocellular carcinoma in comparison to HBV mono-infected individuals. Although HDV only replicates in individuals coinfected or superinfected with HBV, there is currently [...] Read more.
Individuals chronically infected with hepatitis B virus (HBV) and hepatitis Delta virus (HDV) present an increased risk of developing cirrhosis and hepatocellular carcinoma in comparison to HBV mono-infected individuals. Although HDV only replicates in individuals coinfected or superinfected with HBV, there is currently no in vitro model that can stably express both viruses simultaneously, mimicking the chronic infections seen in HBV/HDV patients. Here, we present the HepG2BD cell line as a novel in vitro culture system for long-term replication of HBV and HDV. HepG2BD cells derive from HepG2.2.15 cells in which a 2 kb HDV cDNA sequence was inserted into the adeno-associated virus safe harbor integration site 1 (AAVS1) using CRISPR-Cas9. A Tet-Off promoter was placed 5′ of the genomic HDV sequence for reliable initiation/repression of viral replication and secretion. HBV and HDV replication were then thoroughly characterized. Of note, non-dividing cells adopt a hepatocyte-like morphology associated with an increased production of both HDV and HBV virions. Finally, HDV seems to negatively interfere with HBV in this model system. Altogether, HepG2BD cells will be instrumental to evaluate, in vitro, the fundamental HBV–HDV interplay during simultaneous chronic replication as well as for antivirals screening targeting both viruses. Full article
(This article belongs to the Special Issue Life Cycle of Hepatitis D Virus (HDV) and HDV-Like Agents)
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18 pages, 3486 KiB  
Article
Seasonal Change in Techno-Economic Properties of Waterfront Structural Pinewood
by Ismail Cengiz Y?lmaz, Hamdi Tekin, Mehmet Palanci and ?enay Atabay
Buildings 2024, 14(4), 945; https://doi.org/10.3390/buildings14040945 (registering DOI) - 29 Mar 2024
Abstract
Historical buildings are constructed using a variety of materials, including stone, wood, and combinations thereof. These structures serve as tangible links to the past and are of great importance to cultural heritage, thus necessitating their protection. Throughout history, these buildings and materials have [...] Read more.
Historical buildings are constructed using a variety of materials, including stone, wood, and combinations thereof. These structures serve as tangible links to the past and are of great importance to cultural heritage, thus necessitating their protection. Throughout history, these buildings and materials have been exposed to various environmental conditions, including climate, wind, humidity, and seismic activity. This study focused on the Florya Atatürk Marine Mansion, Istanbul, a coastal structure situated at the shoreline and subject to the effects of wind, moisture, and sea salt. The mansion is primarily constructed from pinewood, and due to the complexity of the material salt can cause deterioration that poses a threat to the building’s cultural and historical value. With a focus on seasonal variations, this study explored the relationship between the mechanical properties and monetary values of the pinewood materials used in the waterfront mansion. To achieve this, samples were naturally aged in a saline environment by the sea and subjected to tensile and bending tests at the end of each season. The resulting mechanical properties were compared to computer simulations using finite element methods. By subtracting the specific depreciation rate of the material at the end of each season, a relationship between mechanical properties and monetary value was calculated and presented in graphical form. It was found that the material’s mechanical properties varied throughout the year, affecting its monetary value in different ways. Therefore, optimal maintenance should be provided before January to preserve the economic value of the material, considering temperature change, exposure to direct sunlight, and humidity, which have direct effects on the front and back parts of the building. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
38 pages, 1310 KiB  
Review
The Role of AI in Hospitals and Clinics: Transforming Healthcare in the 21st Century
by Shiva Maleki Varnosfaderani and Mohamad Forouzanfar
Bioengineering 2024, 11(4), 337; https://doi.org/10.3390/bioengineering11040337 (registering DOI) - 29 Mar 2024
Abstract
As healthcare systems around the world face challenges such as escalating costs, limited access, and growing demand for personalized care, artificial intelligence (AI) is emerging as a key force for transformation. This review is motivated by the urgent need to harness AI’s potential [...] Read more.
As healthcare systems around the world face challenges such as escalating costs, limited access, and growing demand for personalized care, artificial intelligence (AI) is emerging as a key force for transformation. This review is motivated by the urgent need to harness AI’s potential to mitigate these issues and aims to critically assess AI’s integration in different healthcare domains. We explore how AI empowers clinical decision-making, optimizes hospital operation and management, refines medical image analysis, and revolutionizes patient care and monitoring through AI-powered wearables. Through several case studies, we review how AI has transformed specific healthcare domains and discuss the remaining challenges and possible solutions. Additionally, we will discuss methodologies for assessing AI healthcare solutions, ethical challenges of AI deployment, and the importance of data privacy and bias mitigation for responsible technology use. By presenting a critical assessment of AI’s transformative potential, this review equips researchers with a deeper understanding of AI’s current and future impact on healthcare. It encourages an interdisciplinary dialogue between researchers, clinicians, and technologists to navigate the complexities of AI implementation, fostering the development of AI-driven solutions that prioritize ethical standards, equity, and a patient-centered approach. Full article
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27 pages, 2977 KiB  
Article
Charging Behavior Portrait of Electric Vehicle Users Based on Fuzzy C-Means Clustering Algorithm
by Aixin Yang, Guiqing Zhang, Chenlu Tian, Wei Peng and Yechun Liu
Energies 2024, 17(7), 1651; https://doi.org/10.3390/en17071651 (registering DOI) - 29 Mar 2024
Abstract
The rapid increase in electric vehicles (EVs) has led to a continuous expansion of electric vehicle (EV) charging stations, imposing significant load pressures on the power grid. Implementing orderly charging scheduling for EVs can mitigate the impact of large-scale charging on the power [...] Read more.
The rapid increase in electric vehicles (EVs) has led to a continuous expansion of electric vehicle (EV) charging stations, imposing significant load pressures on the power grid. Implementing orderly charging scheduling for EVs can mitigate the impact of large-scale charging on the power grid. However, the charging behavior of EVs significantly impacts the efficiency of orderly charging plans. By integrating user portrait technology and conducting research on optimized scheduling for EV charging, EV users can be accurately classified to meet the diverse needs of various user groups. This study establishes a user portrait model suitable for park areas, providing user group classification based on the user response potential for scheduling optimization. First, the FCM and feature aggregation methods are utilized to classify the quantities of features of EV users, obtaining user portrait classes. Second, based on these classes, a user portrait inventory for each EV is derived. Third, based on the priority of user response potential, this study presents a method for calculating the feature data of different user groups. The individual data information and priorities from the user portrait model are inputted into the EV-optimized scheduling model. The optimization focuses on the user charging cost and load fluctuation, with the non-dominated sorting genetic algorithm II utilized to obtain the solutions. The results demonstrate that the proposed strategy effectively addresses the matching issue between the EV user response potential and optimal scheduling modes without compromising the normal use of EVs by users. This classification approach facilitates the easier acceptance of scheduling tasks by participating users, leading to optimized outcomes that better meet practical requirements. Full article
(This article belongs to the Section E: Electric Vehicles)
18 pages, 2874 KiB  
Article
Fabrication of High-Performance Densified Wood via High-Pressure Steam Treatment and Hot-Pressing
by Weizhi Huang, Yangxi Jin, Yi Guo, Jiaqi Deng, Haoyang Yu and Bobing He
Polymers 2024, 16(7), 939; https://doi.org/10.3390/polym16070939 (registering DOI) - 29 Mar 2024
Abstract
The fabrication of sustainable structural materials with high physical properties to replace engineering plastics is a major challenge for modern industry, and wood, as the most abundant sustainable natural raw material on the planet, has received a great deal of attention from researchers. [...] Read more.
The fabrication of sustainable structural materials with high physical properties to replace engineering plastics is a major challenge for modern industry, and wood, as the most abundant sustainable natural raw material on the planet, has received a great deal of attention from researchers. Researchers have made efforts to enhance the physical properties of wood in order to replace plastics. However, it is also difficult to meet practical demands at a low cost. Herein, we report a simple and efficient top-down strategy to transform bulk natural basswood into a high-performance structural material. This three-step strategy involves partial removal of hemicellulose and lignin via treating basswood by boiling an aqueous mixture of NaOH and Na2SO3, and a high-pressure steam treatment (HPST) was applied to delignified wood followed by hot-pressing, which allowed the wood to absorb moisture uniformly and quickly. HPST-treated dense delignified wood (HDDW) has a tensile strength of ~420 MPa, which is 6.5 times better than natural basswood (~65 MPa). We systematically investigated the various factors affecting the tensile strength of this wood material and explored the reasons why these factors affect the tensile strength, as well as the intrinsic connection between the moisture absorbed through HPST and the increased tensile strength of HDDW. Through our experiments, we realized the enhancement mechanism of HDDW and the optimal experimental conditions for the fabrication of HDDW. Full article
(This article belongs to the Section Biomacromolecules, Biobased and Biodegradable Polymers)
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17 pages, 6650 KiB  
Article
Analysis of the Distribution Pattern of Remaining Oil and Development Potential after Weak Gel Flooding in the Offshore LD Oilfield
by Lizhen Ge, Xiaoming Chen, Gang Wang, Guohao Zhang, Jinyi Li, Yang Liu, Lixiao Xiao, Yuchen Wen, Weifeng Yuan, Ming Qu and Mingxing Bai
Gels 2024, 10(4), 236; https://doi.org/10.3390/gels10040236 (registering DOI) - 29 Mar 2024
Abstract
The LD oilfield is one of the representative offshore oilfields. After weak gel flooding, the recovery rate is significantly improved. However, the oilfield is then in a medium- to high-water content stage, presenting a complex distribution of the remaining oil. The measures for [...] Read more.
The LD oilfield is one of the representative offshore oilfields. After weak gel flooding, the recovery rate is significantly improved. However, the oilfield is then in a medium- to high-water content stage, presenting a complex distribution of the remaining oil. The measures for further enhanced oil recovery (EOR) are uncertain. As a result, it is necessary to clarify the distribution pattern and development potential of the remaining oil during the high-water content period after weak gel flooding. In this study, an online nuclear magnetic resonance (NMR) oil displacement experiment and microscopic oil displacement experiment were conducted, and the mechanisms of weak gel flooding and the distribution pattern of the remaining oil were clarified in the LD oilfield. Additionally, high-multiple water flooding and numerical simulation experiments were conducted to analyze the development potential after weak gel flooding. The results show that the effect of weak gel flooding was more significant in the core of 1500 mD, with an increase in oil recovery of 9% compared to 500 mD. At a permeability of 500 mD, the degree of crude oil mobilization in micropores and small pores caused by weak gel flooding was improved by 29.64% and 23.48%, respectively, compared with water flooding. At 1500 mD, the degree of crude oil mobilization in small pores caused by weak gel flooding was increased by 37.79% compared to water flooding. After weak gel flooding, the remaining oil was primarily distributed in medium and large pores. Microscopically, the remaining oil was dominated by cluster residual oil, accounting for 16.49%, followed by columnar, membranous, and blind-end residual oil. High multiple water flooding experiments demonstrated that weak gel flooding could significantly reduce development time. The ultimate oil recovery efficiency of 500 mD and 1500 mD reached 71.85% and 80.69%, respectively. Numerical simulation results show that the ultimate oil recovery efficiency increased from 62.04% to 71.3% after weak gel flooding. This indicated that the LD oilfield still had certain development potential after weak gel flooding. The subsequent direction for enhanced oil recovery focuses mainly on mobilizing oil in medium pores or clustered remaining oil. This will play a crucial role in further exploring methods for utilizing the remaining oil and increasing the recovery rate. Full article
(This article belongs to the Special Issue Applications of Gels for Enhanced Oil Recovery)
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24 pages, 3505 KiB  
Review
Insect Antimicrobial Peptides as Guardians of Immunity and Beyond: A Review
by Lizhen Zhou, Guanliang Meng, Ling Zhu, Li Ma and Kangkang Chen
Int. J. Mol. Sci. 2024, 25(7), 3835; https://doi.org/10.3390/ijms25073835 (registering DOI) - 29 Mar 2024
Abstract
Antimicrobial peptides (AMPs), as immune effectors synthesized by a variety of organisms, not only constitute a robust defense mechanism against a broad spectrum of pathogens in the host but also show promising applications as effective antimicrobial agents. Notably, insects are significant reservoirs of [...] Read more.
Antimicrobial peptides (AMPs), as immune effectors synthesized by a variety of organisms, not only constitute a robust defense mechanism against a broad spectrum of pathogens in the host but also show promising applications as effective antimicrobial agents. Notably, insects are significant reservoirs of natural AMPs. However, the complex array of variations in types, quantities, antimicrobial activities, and production pathways of AMPs, as well as evolution of AMPs across insect species, presents a significant challenge for immunity system understanding and AMP applications. This review covers insect AMP discoveries, classification, common properties, and mechanisms of action. Additionally, the types, quantities, and activities of immune-related AMPs in each model insect are also summarized. We conducted the first comprehensive investigation into the diversity, distribution, and evolution of 20 types of AMPs in model insects, employing phylogenetic analysis to describe their evolutionary relationships and shed light on conserved and distinctive AMP families. Furthermore, we summarize the regulatory pathways of AMP production through classical signaling pathways and additional pathways associated with Nitric Oxide, insulin-like signaling, and hormones. This review advances our understanding of AMPs as guardians in insect immunity systems and unlocks a gateway to insect AMP resources, facilitating the use of AMPs to address food safety concerns. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Immunology 2.0)
9 pages, 841 KiB  
Article
Evolutionary Model of Signed Edges in Online Networks Based on Infinite One-Dimensional Uniform Lattice
by Zhenpeng Li, Zhihua Yan and Xijin Tang
Mathematics 2024, 12(7), 1026; https://doi.org/10.3390/math12071026 (registering DOI) - 29 Mar 2024
Abstract
The aim of this paper is to study the evolutionary dynamic model for signed edges as observed in online signed social networks. We introduce the incremental mechanism of signed edges behind a simple random walk and explain how this relates to Brownian motion [...] Read more.
The aim of this paper is to study the evolutionary dynamic model for signed edges as observed in online signed social networks. We introduce the incremental mechanism of signed edges behind a simple random walk and explain how this relates to Brownian motion and the diffusive process. We prove how a one-dimensional thermal diffusion equation can be obtained to describe such edge-generating mechanism, and moreover obtain a macroscopic probability distribution of positive and negative edges. The result reveals that the signed edge growth dynamics process can be regarded as a thermodynamic diffusion process. Both empirically and theoretically, we validate that signed network links follow the classic statistic mechanism, i.e., local Brownian motion gives rise to the global emergence pattern of the Gaussian process. The investigation might discover a new and universal characteristic for signed networks, and shed light on some potential applications, such as information spreading, evolutionary games, trust transmission, and dynamic structural balance. Full article
(This article belongs to the Special Issue Modeling and Simulation of Social-Behavioral Phenomena)
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21 pages, 18109 KiB  
Article
Preparation and Performance Study of n-Undecane Phase Change Cold Storage Material
by Luchao Yan, Yang Wang, Shijian Lu, Zhipeng Zhu and Lingling Xu
Materials 2024, 17(7), 1570; https://doi.org/10.3390/ma17071570 (registering DOI) - 29 Mar 2024
Abstract
With the fast development of the cold chain transportation industry, the traditional refrigeration method results in significant energy consumption. To address the national call for energy saving and emission reduction, the search for a new type of energy storage material has already become [...] Read more.
With the fast development of the cold chain transportation industry, the traditional refrigeration method results in significant energy consumption. To address the national call for energy saving and emission reduction, the search for a new type of energy storage material has already become a future development trend. According to the national standard GB/T28577 for the classification and basic requirements of cold chain logistics, the temperature in frozen logistics is typically below −18 °C. In this study, n-undecane with a phase change temperature of −26 °C is chosen as the core material of microcapsules. Poly(methyl methacrylate) is applied as the shell material, with n-undecane microcapsules being prepared through suspension polymerization for phase change cold storage materials (MEPCM). Using characterization techniques including SEM, DSC, FTIR, and laser particle size analysis, the effects of three types of emulsifiers (SMA, Tween-80, Tween-80/span-80 (70/30)), SMA emulsifier dosage, core–shell ratio, and emulsification rate on the thermal performance and micro-surface morphology of n-undecane/PMMA microcapsules were studied. The results indicate that when comparing SMA, Tween-80, and Tween-80/span-80 (70/30) as emulsifiers, the dodecane/PMMA microcapsules prepared with SMA emulsifier exhibit superior thermal performance and micro-surface morphology, possessing a complete core–shell structure. The optimal microstructure and the highest enthalpy of phase change, measuring 120.3 kJ/kg, are achieved when SMA is used as the emulsifier with a quantity of 7%, a core-to-wall ratio of 2.5:1, and an emulsification speed of 2000 rpm. After 200 hot and cold cycles, the enthalpy of phase change decreased by only 18.6 kJ/kg, indicating the MEPCM thermal performance and cycle life. In addition, these optimized microcapsules exhibit favorable microstructure, uniform particle size, and efficient energy storage, making them an excellent choice for the refrigeration and freezing sectors. Full article
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26 pages, 2940 KiB  
Article
Iterative Signal Detection and Channel Estimation with Superimposed Training Sequences for Underwater Acoustic Information Transmission in Time-Varying Environments
by Lin Li, Xiao Han and Wei Ge
Remote Sens. 2024, 16(7), 1209; https://doi.org/10.3390/rs16071209 (registering DOI) - 29 Mar 2024
Abstract
Underwater signal processing is primarily based on sound waves because of the unique properties of water. However, the slow speed and limited bandwidth of sound introduce numerous challenges, including pronounced time-varying characteristics and significant multipath effects. This paper explores a channel estimation method [...] Read more.
Underwater signal processing is primarily based on sound waves because of the unique properties of water. However, the slow speed and limited bandwidth of sound introduce numerous challenges, including pronounced time-varying characteristics and significant multipath effects. This paper explores a channel estimation method utilizing superimposed training sequences. Compared with conventional schemes, this method offers higher spectral efficiency and better adaptability to time-varying channels owing to its temporal traversal. To ensure success in this scheme, it is crucial to obtain time-varying channel estimation and data detection at low SNRs given that superimposed training sequences consume power resources. To achieve this goal, we initially employ coarse channel estimation utilizing superimposed training sequences. Subsequently, we employ approximate message passing algorithms based on the estimated channels for data detection, followed by iterative channel estimation and equalization based on estimated symbols. We devise an approximate message passing channel estimation method grounded on a Gaussian mixture model and refine its hyperparameters through the expectation maximization algorithm. Then, we refine the channel information based on time correlation by employing an autoregressive hidden Markov model. Lastly, we perform numerical simulations of communication systems by utilizing a time-varying channel toolbox to simulate time-varying channels, and we validate the feasibility of the proposed communication system using experimental field data. Full article
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17 pages, 318 KiB  
Article
Shared Protentions in Multi-Agent Active Inference
by Mahault Albarracin, Riddhi J. Pitliya, Toby St. Clere Smithe, Daniel Ari Friedman, Karl Friston and Maxwell J. D. Ramstead
Entropy 2024, 26(4), 303; https://doi.org/10.3390/e26040303 (registering DOI) - 29 Mar 2024
Abstract
In this paper, we unite concepts from Husserlian phenomenology, the active inference framework in theoretical biology, and category theory in mathematics to develop a comprehensive framework for understanding social action premised on shared goals. We begin with an overview of Husserlian phenomenology, focusing [...] Read more.
In this paper, we unite concepts from Husserlian phenomenology, the active inference framework in theoretical biology, and category theory in mathematics to develop a comprehensive framework for understanding social action premised on shared goals. We begin with an overview of Husserlian phenomenology, focusing on aspects of inner time-consciousness, namely, retention, primal impression, and protention. We then review active inference as a formal approach to modeling agent behavior based on variational (approximate Bayesian) inference. Expanding upon Husserl’s model of time consciousness, we consider collective goal-directed behavior, emphasizing shared protentions among agents and their connection to the shared generative models of active inference. This integrated framework aims to formalize shared goals in terms of shared protentions, and thereby shed light on the emergence of group intentionality. Building on this foundation, we incorporate mathematical tools from category theory, in particular, sheaf and topos theory, to furnish a mathematical image of individual and group interactions within a stochastic environment. Specifically, we employ morphisms between polynomial representations of individual agent models, allowing predictions not only of their own behaviors but also those of other agents and environmental responses. Sheaf and topos theory facilitates the construction of coherent agent worldviews and provides a way of representing consensus or shared understanding. We explore the emergence of shared protentions, bridging the phenomenology of temporal structure, multi-agent active inference systems, and category theory. Shared protentions are highlighted as pivotal for coordination and achieving common objectives. We conclude by acknowledging the intricacies stemming from stochastic systems and uncertainties in realizing shared goals. Full article
14 pages, 6457 KiB  
Article
Synthesis and Characterization of Iron-Doped TiO2 Nanotubes (Fe/TiNTs) with Photocatalytic Activity
by S. Mohd. Yonos Qattali, Jamal Nasir, Christian Pritzel, Torsten Kowald, Yilmaz Sakalli, S. M. Fuad Kabir Moni, J?rn Schmedt auf der Günne, Claudia Wickleder, Reinhard H. F. Trettin and Manuela S. Killian
Constr. Mater. 2024, 4(2), 315-328; https://doi.org/10.3390/constrmater4020017 (registering DOI) - 29 Mar 2024
Abstract
One of the most significant global challenges for humans is environmental pollution. The technology to control this problem is the utilization of semiconductors as photocatalysts. In the current study, iron-doped titania nanotubes (Fe/TiNTs) with increased photocatalytic effect were synthesized via a modified hydrothermal [...] Read more.
One of the most significant global challenges for humans is environmental pollution. The technology to control this problem is the utilization of semiconductors as photocatalysts. In the current study, iron-doped titania nanotubes (Fe/TiNTs) with increased photocatalytic effect were synthesized via a modified hydrothermal method. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy (TEM), gas adsorption, electron spin resonance (ESR) and UV–Vis diffuse reflectance spectroscopy (DRS). TEM results indicated that Fe/TiNTs have a tubular and uniform structure with an average outer diameter of 23–48 nm and length of 10–15 µm. ESR and DRS revealed that Fe3+ ions were successfully introduced into the TiNT structure by replacing Ti4+ ions. An enhanced light absorption in the range of 400–600 nm additionally indicated successful doping. The band gap was narrowed as iron wt% was increased. The photocatalytic activity was evaluated by the degradation of methyl orange (MO) in the presence of Fe/TiNTs and TiTNs by monitoring the degradation of MO under UV light irradiation. An acceleration on the hydration of Portland cement was observed in the presence of 2.0 wt% Fe/TiNTs. Fe/TiNTs can be used as a nanomaterial in cement-based building materials to provide self-cleaning properties to the surface of concrete even in indoor environments. Full article
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26 pages, 16774 KiB  
Article
A New Inversion Method for Obtaining Underwater Spatial Information of Subsidence Waterlogging Based on InSAR Technology and Subsidence Prediction
by Xiaojun Zhu, Mingjian Qiu, Pengfei Zhang, Errui Ni, Jianxin Zhang, Li’ao Quan, Hui Liu and Xiaoyu Yang
Water 2024, 16(7), 1002; https://doi.org/10.3390/w16071002 (registering DOI) - 29 Mar 2024
Abstract
Surface waterlogging disasters due to underground mining and geological status have caused the abandonment of fertile land, seriously damaged the ecological environment, and have influenced the sustainable development of coal resource-based cities, which has become a problem that some mining areas need to [...] Read more.
Surface waterlogging disasters due to underground mining and geological status have caused the abandonment of fertile land, seriously damaged the ecological environment, and have influenced the sustainable development of coal resource-based cities, which has become a problem that some mining areas need to face. However, the traditional underwater terrain measurement method using sonar encompasses a time-consuming and labor-intensive process. Thus, an inversion method for obtaining the underwater spatial information of subsidence waterlogging in coal mining subsidence waterlogging areas is proposed, based on differential interferometric synthetic aperture radar (D-InSAR) and the probability integral prediction method. First, subsidence values are obtained in the marginal area of the subsidence basin using D-InSAR technology. Then, the subsidence prediction parameters of the probability integral method (PIM) are inverted by a genetic algorithm (GA) based on the subsidence values. Finally, the underwater spatial information of subsidence waterlogging is calculated on the basis of the prediction parameters. The subsidence waterlogging area in the Wugou coal mine was adopted as the study area, and the underwater spatial information of subsidence waterlogging was inverted by the proposed method. The results show that this method can effectively provide the underwater spatial information of subsidence waterlogging, including the maximum subsidence value, waterlogging volume, subsidence waterlogging area, and underwater terrain in the subsidence waterlogging area. Compared with field-measured data from the same period, the RMSE of water depth is 99 mm, and the relative error is 9.9%, which proves that this inversion method is accurate and can meet engineering precision requirements. Full article
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17 pages, 3699 KiB  
Article
Radiological Parameters for the Detection of Pulmonary Hypertension in Severe Aortic Valve Stenosis and Their Influence on Mortality: Does Sex Matter?
by Joseph Kletzer, Bernhard Scharinger, Ozan Demirel, Reinhard Kaufmann, Michaela Medved, Christian Reiter, Matthias Hammerer, Clemens Steinwender, Stefan Hecht, Kristen Kopp, Uta C. Hoppe, Klaus Hergan and Elke Boxhammer
J. Clin. Med. 2024, 13(7), 1999; https://doi.org/10.3390/jcm13071999 (registering DOI) - 29 Mar 2024
Abstract
Background: Echocardiography has long been established as the primary noninvasive method for diagnosing pulmonary hypertension (PH) prior to transcatheter aortic valve replacement (TAVR) in patients with severe aortic valve stenosis (AS). In recent years, radiological methods for diagnosing PH have been investigated. Measurements [...] Read more.
Background: Echocardiography has long been established as the primary noninvasive method for diagnosing pulmonary hypertension (PH) prior to transcatheter aortic valve replacement (TAVR) in patients with severe aortic valve stenosis (AS). In recent years, radiological methods for diagnosing PH have been investigated. Measurements such as the computed tomography angiography (CTA)-derived pulmonary artery (PA) diameter and PA diameter/body surface area (PA/BSA) have shown promising results regarding their diagnostic strength. However, it has yet to be determined if a patient’s sex has any impact on the effectiveness of these diagnostic measurements. Methods: In all, 271 patients (51.3% male, mean age 82.6 ± 4.8 years) with severe AS undergoing TAVR were separated into male and female groups. The cut-off values for the diagnosis of PH were calculated for the CTA-derived PA diameter and PA/BSA based on different systolic pulmonal artery pressure values (40–45–50 mmHg). Patients were then subclassified according to measurements above or below these PA diameters and PA/BSA cut-off values. A PA diameter ≥29.5 mm and PA/BSA ≥ 15.7 mm/m2 qualified for PH. The 1–5 year survival rate in these cohorts was further analyzed. Results: Patients with a PA diameter ≥29.5 mm showed a significantly higher 1 year mortality rate (p = 0.014). This observation could only be confirmed for the male sex (p = 0.018) and not for the female sex (p = 0.492). As for the PA/BSA, in patients over the cut-off value, no significant increase in mortality was noted in the overall cohort. However, the male patients showed increased 3 year (p = 0.048) and 5 year mortality rates (p = 0.033). Conclusions: The CTA-obtained PA diameter and PA/BSA are both useful in the diagnosis of PH and mortality risk stratification in patients with severe AS undergoing TAVR, especially in males. Male patients with PA ≥ 29.5 mm or PA/BSA ≥ 15.7 mm/m2 seem to be at a higher risk of death during follow-up after undergoing TAVR. In females, no such correlation was observed. Full article
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56 pages, 2800 KiB  
Article
Forecasting Selected Commodities’ Prices with the Bayesian Symbolic Regression
by Krzysztof Drachal and Micha? Paw?owski
Int. J. Financial Stud. 2024, 12(2), 34; https://doi.org/10.3390/ijfs12020034 (registering DOI) - 29 Mar 2024
Abstract
This study firstly applied a Bayesian symbolic regression (BSR) to the forecasting of numerous commodities’ prices (spot-based ones). Moreover, some features and an initial specification of the parameters of the BSR were analysed. The conventional approach to symbolic regression, based on genetic programming, [...] Read more.
This study firstly applied a Bayesian symbolic regression (BSR) to the forecasting of numerous commodities’ prices (spot-based ones). Moreover, some features and an initial specification of the parameters of the BSR were analysed. The conventional approach to symbolic regression, based on genetic programming, was also used as a benchmark tool. Secondly, various other econometric methods dealing with variable uncertainty were estimated including Bayesian Model Averaging, Dynamic Model Averaging, LASSO, ridge, elastic net, and least-angle regressions, etc. Therefore, this study reports a concise and uniform comparison of an application of several popular econometric models to forecasting the prices of numerous commodities. Robustness checks and statistical tests were performed to strengthen the obtained conclusions. Monthly data beginning from January 1988 and ending in August 2021 were analysed. Full article
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28 pages, 6848 KiB  
Article
Telecommuting and Travel Behaviour: A Survey of White-Collar Employees in Adelaide, Australia
by Gheyath Chalabi and Hussein Dia
Sustainability 2024, 16(7), 2871; https://doi.org/10.3390/su16072871 (registering DOI) - 29 Mar 2024
Abstract
COVID-19 prompted a significant number of employees to shift to remote work for the first time, potentially reshaping future work patterns. This study examines the post-COVID impacts on telecommuting, commuting behaviour, travel activities, and lifestyles in the city of Adelaide, South Australia. A [...] Read more.
COVID-19 prompted a significant number of employees to shift to remote work for the first time, potentially reshaping future work patterns. This study examines the post-COVID impacts on telecommuting, commuting behaviour, travel activities, and lifestyles in the city of Adelaide, South Australia. A multivariate nominal logistic regression analysis of 305 post-restriction survey responses revealed that home distance from the CBD, industry, occupation, and income significantly influence post-COVID telecommuting trends. Individuals living over 20 kilometres from the CBD, those in professional or managerial roles, and higher-income earners (>125k) are more prone to regular telecommuting, highlighting the impact of commute lengths, job flexibility, and financial resources on the ability to work remotely. The study revealed a higher adoption of telecommuting post-COVID, with more individuals working from home and telecommuting more often each week. This led to reduced usage of private cars and public transport, indicating a decrease in overall travel frequency. Respondents also adopted flexible work schedules, resulting in fewer peak-hour commutes, which would have resulted in lower congestion and emissions and led to more sustainable travel practices. The study also investigated future telecommuting perspectives, revealing a preference for remote work 3–4 days a week. Some respondents who initially could not telecommute have since considered it feasible and want to adopt it. Notably, about 25% of respondents would even change jobs for flexible, home-based work arrangements. The study’s results suggest that remote work frequency may influence individuals’ future house location preferences. These findings offer valuable insights for sustainable transport and urban planning considerations in the post-COVID era. Full article
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22 pages, 2925 KiB  
Review
Review of Applications of Remote Sensing towards Sustainable Agriculture in the Northern Savannah Regions of Ghana
by Abdul-Wadood Moomen, Lily Lisa Yevugah, Louvis Boakye, Jeff Dacosta Osei and Francis Muthoni
Agriculture 2024, 14(4), 546; https://doi.org/10.3390/agriculture14040546 (registering DOI) - 29 Mar 2024
Abstract
This paper assesses evidence-based applications of Remote Sensing for Sustainable and Precision Agriculture in the Northern Savanna Regions of Ghana for three decades (1990–2023). During this period, there have been several government policy intervention schemes and pragmatic support actions from development agencies towards [...] Read more.
This paper assesses evidence-based applications of Remote Sensing for Sustainable and Precision Agriculture in the Northern Savanna Regions of Ghana for three decades (1990–2023). During this period, there have been several government policy intervention schemes and pragmatic support actions from development agencies towards improving agriculture in this area with differing level of success. Over the same period, there have been dramatic advances in remote sensing (RS) technologies with tailored applications to sustainable agriculture globally. However, the extent to which intervention schemes have harnessed the incipient potential of RS for achieving sustainable agriculture in the study area is unknown. To the best of our knowledge, no previous study has investigated the synergy between agriculture policy interventions and applications of RS towards optimizing results. Thus, this study used systematic literature review and desk analysis to identify previous and current projects and studies that have applied RS tools and techniques to all aspects of agriculture in the study area. Databases searched include Web of Science, Google Scholar, Scopus, AoJ, and PubMed. To consolidate the gaps identified in the literature, ground-truthing was carried out. From the 26 focused publications found on the subject, only 13 (54%) were found employing RS in various aspects of agriculture observations in the study area. Out of the 13, 5 studies focused on mapping the extents of irrigation areas; 2 mapped the size of crop and pasturelands; 1 focused on soil water and nutrient retention; 1 study focused on crop health monitoring; and another focused on weeds/pest infestations and yield estimation in the study area. On the type of data, only 1 (7%) study used MODIS, 2 (15%) used ASTER image, 1 used Sentinel-2 data, 1 used Planetscope, 1 used IKONOS, 5 used Landsat images, 1 used Unmanned Aerial Vehicles (UAVs) and another 1 used RADAR for mapping and monitoring agriculture activities in the study area. There is no evidence of the use of LiDAR data in the area. These results validate the hypothesis that failing agriculture in the study area is due to a paucity of high-quality spatial data and monitoring to support informed farm decision-making. Full article
(This article belongs to the Section Agricultural Technology)
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16 pages, 1198 KiB  
Review
From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults
by Matteo Boattini, André Almeida, Sara Comini, Gabriele Bianco, Rossana Cavallo and Cristina Costa
Viruses 2024, 16(4), 531; https://doi.org/10.3390/v16040531 (registering DOI) - 29 Mar 2024
Abstract
Respiratory syncytial virus (RSV) is increasingly recognized as being implicated in acute illness in older adults, with a significant weight in hospitalizations for respiratory illness and death. By means of a best-evidence review, this paper aims to investigate whether RSV can be considered [...] Read more.
Respiratory syncytial virus (RSV) is increasingly recognized as being implicated in acute illness in older adults, with a significant weight in hospitalizations for respiratory illness and death. By means of a best-evidence review, this paper aims to investigate whether RSV can be considered a forgotten pathogen in older patients, looking at trends in the literature volume and exploring possible epidemiological and clinical features underlying the focus given to it. We then present an assessment of its disease burden and present and future strategies for its reduction, particularly in light of the recent availability of new vaccines. Full article
(This article belongs to the Special Issue RSV Epidemiological Surveillance)
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